Centrifugal type impulse tool



1965 E. B. BURNETT 3,212,292

CENTRIFUGAL TYPE IMPULSE TOOL Original Filed Dec. 12, 1962 3 Sheets-Sheet 1 FIG.

INVENTOR ELMEI? B. BURNETT ATTORNEY Oct. 19, 1965 E. B. BURNETT CENTRIFUGAL TYPE IMPULSE TOOL 3 Sheets-Sheet 2 Original Filed Dec.

FIG. 2

INVENTOR ELMER B. BURNETT BY ,4 A 0 ATTORNEY Oct. 19, 1965 E. B. BURNETT 3,212,292

CENTRIFUGAL TYPE IMPULSE TOOL Original Filed Dec. 12, 1962 3 Sheets-Sheet 3 llll INVENTOR ELMER B. BUR/V577 BY A I AT ORNEY United States Patent 14 Claims. (Cl. 64-26) This application is a divisional application of U.S. patent application Serial #244,151 filed December 12, 1962 by Donald K. Skoog et al. and entitled Impulse Tool.

The present invention relates to impulse tools of the type disclosed in U.S. Patent No. 3,116,617 issued January 7, 1964 to D. K. Skoog and U.S. patent application Serial No. 285,160 filed March 18, 1963 by D. K. Skoog, and more particularly to an improved impulse tool of the centrifugal type.

Heretofore, conventional portable, power operated tools for driving nuts, bolts and screws or for applying a torque to other objects have been of the stall, clutch and impact type. While the stall type and clutch type tools give satisfactory torque control in most applications, these types are larger and hence heavier than the impact type tool. Further the stall type and clutch type tools are slower in operation than the impact type tool. In addition the stall type and clutch type tools provide an undesirable torque reaction to the operator, which torque reaction is not present in a tool of the impact type.

In the impact type of tool the kinetic energy of the rotary hammer (of large mass) is transferred to the spindle (of relatively lower mass) by a collision between the jaws of the hammer and the spindle. These conventional impact tools have several limitations. First the rigid jaws of the hammer and the similar jaws of the spindle are relatively light in order to satisfy the demand of the fabricating industries for a light portable tool. However the forces between the jaws of the hammer and the jaws of the spindle are very high during the time of impact therebetween, with resultant breakage or failure of such jaws and a shorter service life than in other conventional power tools, such as those of the stall or clutch types. Secondly, with these conventional impact tools it is very ditficult to control or limit the final torque on a threaded fastener to a final predetermined value within satisfactory limits of accuracy. Further the impact tools are difficult to manufacture because of their complicated structure and are rather noisy in their operation.

It is the general object of the present invention to avoid and overcome the foregoing and other difiiculties of and objections to prior art practices by the provision of an improved tool of the impulse type which tool has all of the advantages of the stall type, clutch type and impact type tools and none of the disadvantages thereof.

A further object of the present invention is the provision of an impulse type tool which operates in a fluid at low force levels with resultant minimum wear and attendant longer service life than conventional impact tools.

Another object of the present invention is the provision of an impulse tool which is operable to control the final torque on a threaded fastener accurately and precisely ice A further object of the present invention is the provision of an improved tool of the impulse type, the major elements of which tool act to seal dynamically or at high velocity and function as a valve statically or at low velocity.

A still further object of the present invention is the provision of an impulse tool which is lighter in weight and faster in operation than the tools of the stall type and clutch type.

A further object of the preesnt invention is the provision of an impulse tool which is operable to apply a torque or a series of impulses at an angle with respect to the longitudinal axis of the impulse tool.

A still further object of the present invention is to provide a centrifugal type impulse tool which utilizes centrifugal force to form the impulsing seal thereby providing rapid sealing with attendant rapid impulsing.

For a better understanding of the present invention reference should be had to the accompanying drawings, wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. 1 is a side elevational view of the improved tool of the impulse type, shown in engagement with a threaded fastener and with a stationary casing means shown in vertical section;

FIG. 2 is a longitudinal sectional view of the centrifugal .type impulse tool showing the housing means as the driven number;

FIG. 3 is a vertical sectional view along the line 3-3 of FIG. 2 in the direction of the arrows;

FIG. 3a is a View similar to FIG. 3 showing the spindle means connected to the drive means and the housing means connected to the square drive for a fastener socket, the housing means having two pairs of levers to provide means for camming the blade into sealing engagement with the .spindle for rotation in either direction, the device now being operable without the effect of centrifugal force thereon;

FIG. 3b is a horizontal sectional view along the line 3b3b of FIG. 3a in the direction of the arrows.

The aforesaid objects of the present invention and other objects which will become apparent as the description proceeds are achieved by providing an impulse tool for applying a predetermined torque to an object. This impulse tool comprises housing means provided with a cavity adapted to contain a fluid and a recess spindle means rotatable in the housing means and in the fluid, and drive means connected to one of the housing means and the spindle means for impulsing the other of housing means and the spindle means and the object. The other of the housing means and the spindle means are adapted to engage the object. Blade means are reciprocable in the recess. Cam means are carried .by the other. Operating means, such as the recess, are connected to the blade means and are operable to engage the cam means. A first sealing portion is on the housing means and sealing means are on the cam means. The blade means and the cam means and the first sealing portion and the sealing means are operable during a relatively small portion of each revolution of relative rotary movement to dynamically seal off the cavity into a high pressure portion 30 that as the pressure increases in the high pressure portion, torque is applied to the other and to the object.

This centrifugal type impulse tool has blade means reciprocable in the driven element (either the housing means or the spindle means). Cam means are carried by the other element or normally stationary element. Operating means in the driven element are connected to the blade means and are operable by centrifugal force to cause the blade means to engage the cam means, to which the impulse is applied.

While the impulse tool of the present invention may be advantageously employed for applying a torque to objects and as a source of fluid impulses in general, the impulse tool of the present invention is particularly adapted for use in conjunction with applying a torque to a threaded fastener and hence it has been so illustrated and will be so described.

With specific reference to the form of the present invention illustrated in the drawings, and referring particularly to FIG. 1, the impulse tool of the present invention for applying torque to a nut N on a bolt S by a socket 25 is indicated generally by the reference letter T.

As shown in FIG. 1 this impulse tool T has a housing means A adapted to contain a fluid, such as oil F.

In FIGS. 2, 3 blade means, such as blade 245, is reciprocable in the driven element (either housing means A or spindle means B in this case the housing means A,,). Operating means, such as levers 250 (FIG. 2) are disposed in the driven element (i.e. housing means A are connected to the blade 245, and are operable by centrifugal force to cause the blade 245 to engage cam means, such as the spindle cam 246 FIGS. 2, 3 carried by the other or normally stationary element (i.e. spindle means H The impulse is applied to the cam 246.

The housing means A,,, suitably an inner housing, comprises rear end plate 240 (FIG. 2), cylinder 242 (FIGS. 2, 3) and front end plate 244 (FIG. 2). The spindle cam 246 carried by the spindle shaft 16 (FIG. 2) is disposed in the cavity 2,,. The blade 245 is reciprocable in blade slot 248 in housing means A,, and is engageable with levers 250 by means of slots 252 in such blade 245. The levers 250 are pivoted at 254 (FIGS. 2, 3) on the end plates 240 and 244 and have their greater mass on the lower side of pivot 254 as viewed in FIG. 3.

As the inner housing A rotates in counter clockwise direction (FIG. 3) the centrifugal force on the levers 250 forces the blade 245 into engagement with the spindle cam 246 thus sealing off the cavity 2 into a high pressure portion HP when the inner housing A rotates between the land defined by end or seal points S and S of relief slots 256 in the position shown in FIG. 3. Rotation of the inner housing A from S to S compresses the fluid (oil F) in high pressure portion HP and delivers an impulse to the spindle cam 246.

One impulse per revolution of the inner housing A, is delivered to the spindle cam 246, provided the inner housing A reaches a high enough velocity of rotation to enable centrifugal force to act on the levers 250. Multiple impulses/revolution of the inner housing can be achieved by providing plural number of land or 8 -8 sections with a like number of pairs of relief slots 256 disposed thereabout.

As shown in FIGS. 3a, 3b the shaft 16,, (FIG. 3a) of the spindle means B is connected to the output shaft 33 (FIGS. 1, 3a) of a drive means, such as an air motor similar to D (FIG. 1). The shaft 249 (FIG. 3a) of the housing means A,, is connected to the square drive 16a for a fastener socket 25 (FIG. 1). In this embodiment the effect of centrifugal force on the device is eliminated.

Two pairs of levers 250 (FIGS. 2, 3) are utilized to provide means for camming the blade 245 into sealing engagement with the spindle cam 246 during rotation of the spindle cam 246 in either direction. The blade 245 being held in sealing engagement with the cam 246 by the pressure differential between the high pressure portion HP and low pressure portion LP.

It will be recognized by those skilled in the art that the objects of the present invention have been achieved by the provision of an impulse tool which applies a force, namely oil pressure, on the spindle blade and spindle for a short time (namely during the dynamic sealing portion of the operating cycle of the impulse tool) thus providing operation in a fluid at low force levels with resultant minimum wear and attendant longer service life than conventional impact tools.

The impulse tool of the present invention is operable to control the final torque on a threaded fastener accurately and precisely within predetermined practical limits. Further, because of the simplicity of its structure, the impulse tool is easy and economical to manufacture. In addition, the impulse tool provides. relatively quiet operation as compared with conventional impact tools. The impulse ,tool acts as a seal dynamically and as a valve statically; has all of the advantages of the stall type, clutch type and impact type tools and none of the disadvantages thereof; is lighter in weight and faster in operation than the tools of the stall type and clutch type.

The present invention also provides a centrifugal type impulse tool which utilizes centrifugal force to form the impulse seal thereby providing rapid sealing and impulsing.

While in accordance with the patent statutes one best known embodiment of and alternative embodiments of the present invention has been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby.

I claim:

1. An impulse tool for applying a torque to an object, said impulse tool comprising:

(a) housing means provided with a cavity for sealingly containing a fluid and a recess,

(b) spindle means in said housing means and in said fluid,

(c) drive means operatively associated with one of said housing means and said spindle means for causing relative rotary movement between said housing means and said spindle means,

(d) the other of said housing means and said spindle means being adapted to engage said object,

(e) blade means reciprocable in said recess in said one,

(f) cam means carried by said other,

(g) operating means in said recess in said one and connected to said blade means and operable by centrifugal force to cause said blade means to engage said cam means,

(h) a first sealing portion on said housing means,

(i) sealing means on said cam means,

(j) said blade means and said cam means and said first sealing portion and said sealing means being disposed in sealing relation during a relatively small portion of each revolution of said relative rotary movement,

(k) said blade means and said cam means and said first sealing portion and said sealing means being operable during said relatively small portion of each revolution of said relative rotary movement to dynamically seal off a portion of said cavity into a high pressure portion so that the pressure in said high pressure portion of the cavity and on said other increases thereby causing the other of said housing means and said spindle means to rotate with respect to said one and to apply a torque to said object.

2. An impulse tool for applying a torque to an object,

said impulse tool comprising:

(a) housing means provided with a cavity for sealingly containing a fluid and a recess,

(b) spindle means in said housing means and in said fluid,

(c) drive means connected to one of said housing means and said spindle means for causing relative rotary movement between said housing means and said spindle means,

(d) the other of said housing means and said spindle means being adapted to engage said object,

(e) blade means reciprocable in said recess in said other,

(f) cam means carried by said one,

(g) operating means in said recess in said other and connected to said blade means,

(h) a first sealing portion on said housing means,

(i) sealing means on said cam means and engageable with said operating means to cause said blade means to engage said cam means,

(j) said blade means and said cam means and said first sealing portion and said sealing means being disposed in sealing relation during a relatively small portion of each revolution of said one,

(k) said blade means and said cam means and said first sealing portion and said sealing means being operable during said relatively small portion of each revolution of said one to dynamically seal off said cavity into a high pressure portion and a low pressure portion so that the pressure in said high pressure portion of the cavity and on said other increases and said blade means is maintained in sealing engagement with said cam means by the differential pressure between said high pressure portion and said low pressure portion thereby causing said other to rotate with respect to said one and to apply a torque to said object.

3. The impulse tool recited in claim 1 wherein said drive means is connected to said housing means.

4. The impulse tool recited in claim 1 wherein said drive means is connected to said spindle means.

5. The impulse tool recited in claim 1 wherein said blade means and said operating means are in said housing means.

6. The impulse tool recited in claim 1 wherein said blade means and said operating means are in said spindle means.

7. The impulse tool recited in claim 1 wherein said cam means and said sealing means are on said housing means.

8. The impulse tool recited in claim 1 wherein said cam means and said sealing means are on the spindle means.

9. The impulse tool recited in claim 2 wherein said drive means is connected to said housing means.

10. The impulse tool recited in claim 2 wherein said drive means is connected to said spindle means.

11. The impulse tool recited in claim 2 wherein said blade means and said operating means are in said housing means.

12. The impulse tool recited in claim 2 wherein said blade means and said operating means are in said spindle means.

13. The impulse tool recited in claim 2 wherein said cam means and said sealing means are on said housing means.

14. The impulse tool recited in claim 2 wherein said cam means and said sealing means are on said spindle means.

References Cited by the Examiner UNITED STATES PATENTS 2,144,089 1/39 Stageberg 1925 8 2,564,212 8/51 Ramsey 19258 3,116,617 1/64 Skoog 64-26 BROUGHTON G. DURHAM, Primary Examiner.

FRANK SUSKO, ROBERT C. RIORDON, Examiners. 

1. AN IMPULSE TOOL FOR APPLYING A TORQUE TO AN OBJECT, SAID IMPULSE TOOL COMPRISING: (A) HOUSING MEANS PROVIDED WITH A CAVITY FOR SEALINGLY CONTAINING A FLUID AND A RECESS, (B) SPINDLE MEANS IN SAID HOUSING MEANS AND IN SAID FLUID, (C) DRIVE MEANS OPERATIVELY ASSOCIATED WITH ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS FOR CAUSING RELATIVE ROTARY MOVEMENT BETWEEN SAID HOUSING MEANS AND SAID SPINDLE MEANS, (D) THE OTHER OF SAID HOUSING MEANS AND SAID SPINDLE MEANS BEING ADAPTED TO ENGAGE SAID OBJECT, (E) BLADE MEANS RECIPROCABLE IN SAID RECESS IN SAID ONE, (F) CAM MEANS CARRIED BY SAID OTHER, (G) OPERATING MEANS IN SAID RECESS IN SAID ONE AND CONNECTED TO SAID BLADE MEANS AND OPERABLE BY CENTRIFUGAL FORCE TO CAUSE SAID BLADE MEANS TO ENGAGE SAID CAM MEANS, (H) A FIRST SEALING PORTION ON SAID HOUSING MEANS, (I) SEALING MEANS ON SAID CAM MEANS, (J) SAID BLADE MEANS AND SAID CAM MEANS AND SAID FIRST SEALING PORTION AND SAID SEALING MEANS BEING DISPOSED IN SEALING RELATION DURING A RELATIVELY SMALL PORTION OF EACH REVOLUTION OF SAID RELATIVE ROTARY MOVEMENT, (K) SAID BLADE MEANS AND SAID CAM MEANS AND SAID FIRST SEALING PORTION AND SAID SEALING MEANS BEING OPERABLE DURING SAID RELATIVELY SMALL PORTION OF EACH REVOLUTION OF SAID RELATIVE ROTARY MOVEMENT TO DYNAMICALLY SEAL OFF A PORTION OF SAID CAVITY INTO A HIGH PRESSURE PORTION SO THAT THE PRESSURE IN SAID HIGH PRESSURE PORTION OF THE CAVITY AND ON SAID OTHER INCREASES THEREBY CAUSING THE OTHER OF SAID HOUSING MEANS AND SAID SPINDLE MEANS TO ROTATE WITH RESPECT TO SAID ONE AND TO APPLY A TORQUE TO SAID OBJECT. 